This invention primarily relates to passenger side air bags deployed from an instrument panel of a vehicle.
As shown in prior art FIG. 13, a conventional passenger side air bag 20 is inflated by an air bag inflator 280. The air bag 20 typically has a single inflatable chamber 330 inflated by gas from the inflator 280. The face portion or front panel 320 of the air bag 20 impacts the vehicle occupant 22 across the chest, shoulders and head. As the vehicle occupant assumes a seated position closer to the vehicle's instrument panel and away from the seat back 26 of the seat 24, the velocity at which the air bag impacts the vehicle occupant increases. If the vehicle occupant's body is on or near the cover of the air bag module at the time of air bag deployment, the level of interaction between the vehicle occupant and the air bag is further elevated.
To reduce injuries to occupants including children, infants in child seats and occupants seated in out-of-position orientation, some newer, more complicated systems propose controlling the rate of air bag inflation by use of various sensors to determine the weight, size or seat location of the occupant to be protected. These sensors are costly and very sophisticated and require a very high degree of reliability to insure they function over the life of a vehicle.
To date none of the systems commonly used can accommodate the deployment of an air bag towards an infant in an infant seat located upon the front seat of a vehicle and facing the rear of a vehicle. Accordingly all vehicle manufacturers provide warnings against such a use of the child seat or alternately provide a means for manually deactivating the air bag.
With reference to prior art FIG. 14, it has been proposed that an inflatable cushion or air bag can be formed with two air bags 21a and 21b, which when inflated are spaced apart (see numeral 360) from each other. When these air bags are inflated, they will take the shape shown in which the space 360 is positioned in front of the normally seated vehicle occupant 22, thereby avoiding contact with the vehicle occupant's head. The air bag-occupant loading is primarily by the two air bags against the right and left sides of the vehicle occupant's torso and the right and left shoulders of the vehicle occupant 20. The use of the above system leads to high loads being created against the out-of-position occupant.
In the United States of America, the National Highway Transportation Safety Administration test criteria of a 1-year-old, a 3-year-old, a 6-year-old; a 105 pound female (5th percentile) are each considered sufficiently different to warrant separated criteria for air bag deployment beyond that of a normal size and weight adult vehicle occupant. Similarly, pregnant women have unique requirements to insure survivability of the infant they are carrying. These and other factors make the design and construction of such safety devices very complex while no other device, other than the seat belt, is credited with saving more lives and minimizing the occurrence of serious injury.
It is a primary objective of the vehicle occupant safety restraints industry to provide vehicle occupant restraint devices with a maximum range of safety for the greatest number of potential uses at the highest possible reliability while still being affordably priced. In science and engineering a constant truth is that “simplicity leads to reliability.” The trend toward complex sensors and controls increases the number of components, which inherently leads to increasing the risk of a component malfunction that reduces the overall reliability. To avoid this problem engineers are forced to design in redundancy, which further drives up cost.